1. Field of the Invention
This invention relates to a disc loading apparatus for an optical disc player, and more particularly a disc loading apparatus for an optical disc player, which uses a single motor to move a tray horizontally and vertically with a disc put therein, thereby loading the disc into a turning station.
2. Description of the Prior Art
Generally, an optical disc player is an apparatus which carries out playback of the sound recorded on a disc by moving a tray horizontally and vertically with the disc put therein into a loading apparatus to load the disc into a turning station, and then projecting a laser beam onto the surface of the disc during rotation of a turntable. The player usually includes two loading motors to execute the loading of the disc.
As shown in FIGS. 1 and 2 of the accompanying drawings, the prior disc loading apparatus for the optical disc player comprises a main plate 101 integrally having opposite side plates each formed with a pair of vertically elongated holes 102, two motors 103 and 104 disposed on the main plate to provide power for the horizontal and vertical movements, respectively, and reduction gears 106 and 107 for the horizontal and vertical movements provided to reduce the power transmitted from the motors 103 and 104 to them via power transmission belts 105.
Further, each of the opposite side plates of the main plate 101 has a movable plate 110 disposed on its exterior surface and a support plate 113 disposed on its interior surface. The movable plate 110 is provided with a pair of slots 108 each shaped to have horizontally extending end portions and a sloping portion interconnecting the end portions, as shown in FIG. 3, and a rack 109 formed on its interior surface. The support plate 113 is provided with a plurality of guide projections 111 and a pinion 112 for the horizontal movement of the tray. At its one side, each support plate 113 is fixedly supported on each movable plate 110 via support pins 114, and pinion 112 disposed at the other side of the support plate is meshed with the reduction gear 106 for the horizontal movement.
With this construction, when the motor 103 for the horizontal movement is driven to perform the horizontal movement of the tray 115, the tray is moved in a horizontal direction, i.e., from the position shown if in FIG. 3a to that shown in FIG. 3b through the arrangement in which guide grooves formed in the opposite sides and lower surface of the tray is engaged with the guide projections 111 of the support plate 113 and a rack 117 formed at one side of the lower surface of the support plate 113 and a rack 117 formed at one side of the lower surface of the tray is meshed with the pinion 112 disposed on the support plate, as shown in FIG. 2a.
Meanwhile, when the motor 104 for the vertical movement is driven to perform the vertical movement of the tray, the tray is moved in a vertical direction, i.e., from the position shown in FIG. 3c to that shown in FIG. 3d through the arrangement in which a pinion 118 for the vertical movement disposed on the base surface of the main plate 101 is meshed at one side with the rack 109 of the movable plate 110 and at the other side with the reduction gear 107 for the vertical movement, as shown in FIG. 1. At this time, the motors 103, 104 may be controlled by separate control means (not shown) in a control section to selectively carry out forward and reverse rotations.
Operation of the loading apparatus thus constructed will now be described in more detail with reference to FIGS. 2 and 3.
First, in the action of loading the tray with the disc put therein into the loading apparatus, when the user puts the disc in the tray 115, and then pushes a loading button (not shown), the horizontal movement motor 103 is rotated counterclockwise, and the rotational force of the motor is transmitted to and reduced by the reduction gear 106. Then, the reduced force is transmitted to the horizontal movement pinion 112 of the support plate 113 to rotate it. The rotation of the pinion 112 is converted into horizontal linear motion by the rack 117 formed at one side of the lower surface of the tray and meshed with the pinion. As a result, the tray 115 is moved horizontally in the direction of the arrow from the position as shown in FIG. 3a to that as shown in FIG. 3b.
Then, after completion of the horizontal movement of the tray, the horizontal movement motor 103 is turned off, and at the same time the vertical movement motor 104 is turned on to rotate counterclockwise. The rotational force of the motor 104 transmitted to the reduction gear 107 via the belt 105 is reduced by the gear, and then teansmitted to the pinion 118 which is disposed on the base surface of the main plate 101 and meshed with the rack 109 of the movable plate 110. Then, the rotation of the pinion 118 is converted into linear motion by the rack 109 so that the movable plate is moved horizontally in the direction shown by the arrow in FIG. 3b, i.e., in the leftward direction as viewed in the figure. At the same time, as shown in FIG. 3c, the support pins 114 attached to the support plate 113 are displaced to their lower positions along the sloping portions of the slots 108 of the movable plate 110, while being guided by the vertically elongated holes 102 of the main plate 101. As a result, the tray 115 engaged with the projections 111 of the support plates 113 descends vertically. That is, the horizontal movement of the movable plate 110 causes the vertical movement of the tray 115 by the vertical height of the sloping portion of each slot 108.
After completion of the vertical movement of the tray through the procedure set forth above, the tray is in the state shown in FIG. 3d. Thereafter, the turntable 120 mounted on the main plate 101 is inserted into a guide opening 121 formed in one side of the tray. At this time, the top of the turntable is positioned higher than the upper surface of the tray such that the disc 119 put in the upper portion of the tray is set on the turntable, as shown in FIG. 2b. Then, upon completion of the setting of the disc, the vertical movement motor 104 is turned off, so that the disc loading operation is completed.
After completion of the disc loading operation, the playback of the sound recorded on the disc 119 is performed by projecting the laser beam onto the surface of the disc by separate means (not shown), while rotating the turntable 120 with the disc set thereon.
Meanwhile, "ON" and "OFF" of the horizontal and vertical movement motors 103 and 104 may be controlled by separate switching means (not shown) in the control section. Also, unloading of the disc for withdrawing or exchanging the loaded disc is carried out in the reverse order to the loading action stated above.
As described above, however, the prior art loading apparatus needs two motors for moving horizontally and vertically the tray, the complex power transmission means for transmitting the power of the motors, and the switching means for controlling "ON" and "OFF" of the motors at the control section to allow the horizontal and vertical movements of the tray to be executed continuously as single action. The requirements of a plurality of these parts result in higher manufacturing cost and lower productivity.